Todas as questões do ENEM

                   Fake news could ruin social media, but there’s still hope

by: Guðrun í Jákupsstovu

Camille Francois, director of research and analysis at Graphika, told the audience of her talk at TNW Conference:

“Disinformation campaigns, or fake news is a concept we’ve known about for years, but few people realize how varied the concept can be and how many forms it comes in. When the first instances of fake news started to surface, they were connected with bots. These flooded conversations with alternative stories in order to create noise and, in turn, silence what was actually being said”.

According to Francois, today’s disinformation campaigns are far more varied than just bots – and much harder to detect. For example, targeted harassment campaigns are carried out against journalists and human-rights activists who are critical of governments or big organizations.

“We see this kind of campaigns happening at large scale in countries like the Philippines, Turkey, Ecuador, and Venezuela. The point of these campaigns is to flood the narrative these people try to create with so much noise that their original message gets silenced, their reputation gets damaged, and their credibility undermined. I call this patriotic trolling.”

There are also examples of disinformation campaigns mobilizing people. This was evident during the US elections in 2016 when many fake events suddenly started popping up on Facebook. One Russian Facebook page “organized” an anti-Islam event, while another “organized” a pro-Islam demonstration. The two fake events gathered activists to the same street in Texas, leading to a stand-off.

Francois explains how amazed she is that, in spite of social media being the main medium for these different disinformation campaigns, actual people also still use it to protest properly.

If we look at countries, like Turkey – where there’s a huge amount of censorship and smear campaigns directed at human right defenders and journalists – citizens around the world and in those places still use social media to denounce corruption, to organize human rights movements and this proves that we still haven’t lost the battle of who owns social media.

This is an ongoing battle, and it lets us recognize the actors who are trying to remove the option for people to use social media for good. But everyday you still have people all over the world turning to social media to support their democratic activities. This gives me hope and a desire to protect people’s ability to use social media for good, for denouncing corruption and protecting human rights.

Adapted from:<https://thenextweb.com/socialmedia/2018/05/25/> . Access 09 Oct. 2018.

Glossary

bot: (short for "robot"): um programa automático que roda na Internet; to flood: inundar; trolling: fazer postagem deliberadamente ofensiva para provocar alguém; popping up: surgir, aparecer; stand-off: impasse: smear campaigns: campanhas de difamação.

O dióxido de titânio, além de ser empregado como aditivo alimentar, é comumente usado para pigmentação branca em tintas, papel e plásticos. É também um ingrediente ativo, em protetores solares baseados em minerais, usado para a pigmentação com o objetivo de bloquear a luz ultravioleta. Além disso, o óxido também é usado em alguns chocolates para dar uma textura suave; em donuts, para fornecer cor; e em leites desnatados, para dar uma aparência mais brilhante, mais opaca, o que torna o produto mais saboroso.

Uma das reações utilizadas para a sua produção é a cloração de um mineral de titânio (ilmenita) cuja equação é a seguinte:

x FeTiO3 (s) + y Cl2 (g) + z C(s) → a FeCl2 (s) + bTiO2(s) + c CO2 (g)

Os números para os coeficientes x, y, z, a, b, c, que tornam essa equação balanceada, são, respectivamente:

Aproveitando uma “promoção”, Maria conseguiu comprar uma mercadoria pela fração do seu preço original. O percentual de desconto foi de

A corrupção é, sem dúvida, um dos temas mais recorrentes na imprensa brasileira dos últimos anos. Partidos e políticos são denunciados por desvios de verba, no uso ilegítimo do poder público, com o intento de privilegiar uma empresa ou instituição privada.

No caso brasileiro, a corrupção é um (a)

Observe a imagem de um trecho da maior floresta úmida do planeta:

Essa floresta é abrangida pelo clima:

Analise o texto a seguir:

A China surpreendeu ontem ao anunciar medidas de estímulo para proteger sua economia. O pacote de incentivos que inclui redução de impostos tranquilizou os investidores. Segundo o comunicado, a política fiscal será mais “proativa” e coordenada com a política monetária. Do outro lado da disputa, o presidente norte-americano Donald Trump usou o Twitter para defender as tarifas dos EUA às importações, que, segundo ele, “são ótimas”. Ele ainda afirmou que os EUA são o “cofre que está sendo roubado”.

CORRÊA, M.; RIBEIRO, A. Pacote anti-Trump. O Globo. Economia, 26 jul. 2018, p. 19.

No texto, é abordada a seguinte situação geoeconômica e geopolítica:

Analise a imagem abaixo:

As trocas comerciais no interior do mesmo bloco regional são mais intensas na

Analise o texto sobre deslocamento populacional:

Diversas regiões do planeta, por suas características naturais, são bastante vulneráveis aos efeitos do aquecimento global, como as situadas nas áreas semiáridas da África Subsaariana; os países insulares do Oceano Pacífico; as regiões tropicais da América e da Ásia, afetadas por violentas tempestades (tufões, furacões e ciclones) ou por prolongadas chuvas torrenciais, como no sul e sudeste da Ásia. Dessas regiões deslocam-se indivíduos em decorrência de inundações, da elevação do nível do mar, de secas prolongadas, dentre outros fatores.

LUCCI, A.; BRANCO, A.; MENDONÇA, C. Território e Sociedade no Mundo Globalizado. São Paulo: Saraiva, 2017, p. 187. Adaptado.

Devido às causas mencionadas, o indivíduo que se desloca de uma região a outra é especificamente denominado migrante

Dois corpos pontuais portando cargas respectivamente iguais a Q e Q’ estão em repouso conectados por uma mola. Quando a carga de um deles é dobrada, passando de Q para 2Q, a extensão da mola diminui na nova posição de equilíbrio. Quatro hipóteses foram elaboradas sobre os sinais das cargas:

I: Q > 0 e Q’ > 0

II: Q > 0 e Q’ < 0

III: Q < 0 e Q’ > 0

IV: Q < 0 e Q’ < 0

São compatíveis com o fenômeno descrito as hipóteses

                                         T E X T

                          Can you learn in your sleep?

      Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

      Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

      The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

      New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

      For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

      However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

      Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

      Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

      To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

      "When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

      Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

      "Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

      Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

      Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

      So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

                                From: https://www.medicalnewstoday.com/articles/Mar/2018